Fuel system for internal combustion engines



May 9, 1933. R, F. BRACKE FUEL SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Feb. 26. 1931 2 Sheets-Sheet l May 9, 1933. R. F. BRAcKE FUEL SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Feb. 26. 1931 2 Sheets-Sheet 2 tlllmc QN if Pafented May 9, 1933 UNITED STATES PATENT OFFICE ROBERT r. BnacxE, oF CHICAGO, ILLINoIs, .assIciNoIal BY MEsNE AssIGNMENTs, 'ro

LYNN A. WILLIAMS, or EvaNs'roN; ILLINOIS, AND CLIFFORD c. BRADBUNY, or

GLENcoE, ILLINOIS, As TRUs'rEEs FUEL SYSTEM FOB ITERNAL COMBUSTION IEJIGIBTES Application mea February l2e, 1931. serial No. 518,470.

My invention relates to fuel supply systems Afor internal combustion engines and more particularly to fuel systems for two cycle engmes.

; It is the object of the present invention to rovide means for lifting fuel from'a low evel tank to the carburetor or fuel metering or injection device mounted on or near the' motor and at a level higher than the main ;supply tank. v s

It is a further object of this invention to rovide simple and eflicient means for lifting uel from a low level to a conventional gravity feed carburetor -moufited on or near the linotor. It is a further and more specific object of the present invention to provide means for utilizing crankcase compression in atwo cycle motor for the purpose of lifting fuel from a low level supply tank to a carburetor 241 or fuel metering device mounted on the motor.

" The above features and others not specifically set forth above will be more fully `the connections between the .crank case, the

fuel supply tank, and the carbureter, which includes a transverse sectional viewof lthe rotating valve as positioned in 2 but showing the channels in the valve utilized for by-passing a portionof the compressed charge to the fuel supply tank.

Referring now to the drawings, and particularly to Fig. 1, there is shown more or less j passed to the firing cylinders of the engine,

in outline an internal combustion engine 2 of the portable type in which a rotary valve 3 shown dotted rotates in unison with the crankshaft of the engine and is set with relation to the rotation of the crankshaft for the proper intervals of opening and closing to permit full and complete charges to be fed into the crankcase chamber, where these charges are subsequently compressed and byas will be more fullyhereinafter described. The engine 2 as shown is secured to the ster-n of an outboard motor boat.f1, and a main fuel supply tank 5 suitably located forward of the engine and'secured to the floor '6 of the boat to guard against displacement is suppliedY with a suitable feed line or pipe to conduct fuel therefrom to the carburetor of the engine.

A fuel or pipe line-7 communicatesat its one end 8 with the bottom of the fueltank 5 and its other end 9 with the fuel chamber of the carburetor 10 associated with the engine 2. A second pipe line -11 communicates at its one end with-the top of the fuel tank 5 and at its opposite end with a port l2 extending through the rotary valve housing 13 and serves to by-pass portions of compressed fuel charges from the crankcase chamber of the engine into. the tank 5 to maintain the liquid fuel contained therein under suitable pressure, as will be more fully hereinafter described. A cooling cylinder interposed in the pipe line 1l between the port 12 and the top of the fuel supply tank 5 comprises a 80 cylinder l5 of suitable metal such as copper, having a plurality of openings 16 parallel with the major axis of the same and extending therethrough. Cap members 17 and 18 are provided which have threaded engagement with the threaded end portions of the cylinders l5, and tapped openings 20 extend.-

-in through the same receive the threaded en s of the respective sections of the pipe 11;

crankcase.

' shown in transverse section the rotary valve 3 and the housing 13 within which the valve rotates in unison with the crankshaft of the engine 2. The housing 13 is interposed between the crankcase 19 and the carburetor 10, of which fragmentary portions are shown, the housing 13 being suitably supported or secured to the crankcase 19. Ports 21 and 22 separated by a partition 23 are provided in the valve 3 and lie in planes parallel with the major axis ofthevalve'3. The ports 21 and 22 register with diametrically opposite openings 24 and 25 in the housing 13 during a predetermined degree o f rotation of the valve 3 to permit the entry of fuel charges,

into the crankcase chamber 19. The openings 24 and 25 in the housing 13 are aligned or matched respectively wlth like contoured openings 26 in the crankcase 19 and the discharge opening 27 of the carburetor 10.

In a two-cycle internal combustion en ine, the rotary valve 3 rotates in unison wit the crankshaft "of the engine, and' is so set with relation to the rotation of the same that onthe intake'stroke of the pistons, that is, when the pistons are moving to firing osition, the valve 3 is open to permit the uel mixture from the carburetor 10 to be inducted into the crankcase chamber 19 through the ports 21 and 22. 'As the pi'stons reach firing position the valve 3 will have been rotated to positionl the separating wall 23 between the ports 21 and'22 with relation to the diametrically opposite openings 24 and 25 of the housing 13 to close the ports 21 and 22, as clearly illustrated in Fig. 2. The -pistons on their return movement from firing osition will now compress the fuel mixture lnducted into the crankcase chamber 19 and this compressed mixture will be subsequently passed vforward of the pistons as the pistons reach the end of their travel from firing position in the usual manner.

The valve 3, as shown in Fig. 2, rotates in a direction indicated by the arrow and the ports 21 and 22 are in closed position to subject the fuel mixture or charge in the crankcase chamber 19 to compression under the influence of piston movement, which in this instance is from firing position. It is this compressed fuel mixture or charge in the chamber 19 that is utilized and by-passed to the main fuel supply tank to place the fluid therein under pressure to assure a continuous supply of fuel at all engine speeds.

As shown in'Fig. 2, the rotatin valve 3 1s provided with a pair of diametrically opposite horizontally disposed channels 30 and 31 of predetermined length formed in the peripheral face of the same. The channels 30 and 31 are positioned just below the bottom edge of the port openings 21 and 22 and in approximate vertical alignment therewith, and are adapted to register alternately with the port opening 12 as the valve 3 rotates in unison with the crankshaft of the engine. The valve 3, as shown in Fig. 2, hasl 7 just moved to closed position to position the forward end of the channel V30 in registry with the port opening 12. This registry of the channel 30 with the port 12 now permits a portion of the compressedfuel charge in the crankcase .19 to pass therethrough, but only for such interval as the. channel 30 remains in communication with crankcase 19.' During the interval that the ports 21 and 22 are closed, the fuel charge contained in the crankcase 19 is subjected to compression due to the engine piston movement, as already described, andduringthe interval that the vchannel 30 is in communication with the terval of time that the channels 30 and 31 9 are alternately in communication with the crankcase. The crankcase 19 of the engine becomes heated during continued engine, operation Y and the compressed fuel char es that are by- 10 passed to the fuel tank are t us heated dne to this condition. These char es, however,

pass through the openings' 16 o the cylinder 15 and are thus eooledto an appreciable ex` tent before entering the supply tank 5. 105 i Should backring occur, the ignited gases' will necessarily pass through the cylinder 15 and be cooled and extinguished before 'en-A tering the fuel tank 5,'precluding the possibility of firing the fuel therein. ne

My invention, when applied to a design of a two cycle motor illustrated, has the addi-V tional advantage of not requiring a cheek valve in the crankcase-to-tank line as would be desirable if applied to che three-port type 1?- oftwo cycle motor in which the pistons 11ncover a third port'at the end of the suction stoke in the crankcase to 'permit the carburetor to deliver a charge therein.

In the fuel-system as above described L haviaI devised a means whereby .the usual pumpfor maintaining the fuel in the supply tank to assure a constant fuel supplyfor all l Y and substantially constant pressure in the l!"V fuel supply tank which is automatically maintained during engine operation.

I claim:

1. The combination of an internal combustion engine with a crankcase wherein a fuel charge is compressed by engine piston movement, an engine controlled valve and a passage therein for admitting a fuel charge to the crankcase prior to the compression action of said piston, a fuel supply tank and means associated with said valve for subsequently by-passing a predetermined portion of said charge to this fuel tank to maintain a pressure therein.

2. The combination of an internal combustion engine with a crankcase wherein a fuel charge is compressed by engine pistonl movement, an engine controlled valve and a passage therein for admitting a fuel charge from the engine carburetor to the crankcase, a fuel supply tank for the engine carburetor and means associated with said valve effective during a portion of the engine piston movement to compress the fuel charge in the crankcase to by-pass a predetermined portion of said charge to the fuel supply tank t0 maintain the fuel therein under pressure.

3. The combination of an internal combustion engine with a crank case for receiving a fuel charge, an engine controlled valve and a passage therein for admitting a fuel charge to the crank case and a subsequent closing of said passage for the compression of the charge in the crank case by engine piston movement, a fuel supply tank and means associated with said valve connecting said crank case with said fuel tank for by-passing a portion of the compressed charge to said tank to maintain a pressure therein.

4. The combination of an internal combustion engine with a crank case for receiving a fuel charge, a valve rotating in unison with the crank shaft of the engine, a passage in said valve for admitting a fuel charge to the crank case when open and during closure to permit the compression of the charge in the crank case by engine piston movement, a pair of diametrically opposite passages in said valve connecting sai crank case with said fuel tank during the compression period of said charges in said crank case to by-pass a portion of such compressed charges to said tank to maintain a pressure therein.

5. The combination of an internal combustion engine with a crank case for receiving a fuel charge, a valve rotating in unison with the crank shaft of the engine and a passage therein alternately opened and closed to permit admission of a fuel charge to the crank case and the compression of said fuel charge therein due to engine piston movement, a housing for said valve and an opening therein, a connection between said opening and a main fuel supply tank, and a pair of diametrically opposite passages in said valve for connecting Said opening with said crank case during the compression of the fuel charge therein to by-pass a portion of such compressed charge to said tank to maintain a pressure therein.

6. The combination of an internal combustion engine with a crankcase for receiving a fuel charge, a valve rotating in unison with the crank shaft of the engine, a passage therethrough alternately opened and closed for the admission of a fuel charge to the crankcase and the subsequent compression of the same therein, a housing for said valve and an opening therein, a fuel supply tank and a connection between the fuel tank and the engine carburetor, a second connection between said fuel tank and said opening, a pair of diametrically opposite passages in said valve connecting said crankcase and said opening during the compression of the fuel charges in the crankcase and for such time as said second passages remain in communication with said crankcase to by-pass such portion of the compressed charges through said second connection to the fuel tank to maintain a pressure therein.

7 The combination of an internal combustion engine with a crankcase for receiving. fuel charges which are subsequently compressed therein, an engine controlled valve and a passage therethrough when open to admit a fuel charge to the crankcase and when closed to permit the compression of said charge in the crankcase, a fuel supply tank, means associated with said valve for connectmg said crankcase with said fuel tank for by-passmg a portion of the compressed charges to said tank to maintain a pressure therein and means interposed between said tank and said crankcase for cooling such charges before entering said tank.

8. The combination of internal combustion engine with a crankcase wherein a fluid is compressed by the engine piston movement, a fuel supply tank, a fuel feed line from the tank to t e engine, and valve means positively actuated by the engine in timed relation to the engine cycle for by-passing a portion of the compressed fluid from the crankcase into said supply tank to maintain a pressure therein.

9. The combination of internal combustion engine with a crankcase wherein a fluid is compressed by the engine piston movement, a

carburetor, a fuel supply tank in communication with said carburetor, and an en 'ne controlled valve for passage of fuel rom the carburetor to the crankcase, means cooperating with said valve for by-passing a portion of the compressed fluid in said crankcase into said fuel supply tank to maintain a pressure therein.

10. The combinationof internal combustion engine with a crankcase wherein a fuel charge is compressed by engine piston moveengine between said carburetor an i www1 ment, a carburetor, a fuel st'lppl'y tank located below the level of the carburetor, a fuel su ply line extending from the fuel tank to e carburetor, a rotary valve actuated b sal crankcase, means cooperating with said valve whereby a portion of the compressed fluid charge is by-passed from said crankcase to c said fuel tank for thepurpose of forcing fuel from said-tank to said carburetor.

In witness whereof, I hereunto subscribe my name this 18th da of February', 1931.'

ROB RT F. BRACKE. 

